Monoprice SCSI (HPDB) 68 Female to IDC 50 Female Adapter (100076) The IDC 50 connector is a 50-pin 8-bit SCSI "header" connector used for internal-type ribbon cables It is also known as the "Alterative 2" connector It has parallel 25-pin rows and resembles an older ATA/IDE drive cable except that it is wider and has more pins The HPDB 68 connector is a 68-pin 16-bit SCSI-2 connector used for both internal and external connections (plastic for internal and metal for external) It has parallel 34-pin rows but has the pins much closer together and is therefore narrower than the IDC 50 connector